Can You Sand Resin?

Resin is a great material to work with. It can be poured into any mold to make a perfect copy, drying hard and fast. Not only that, but colored resins dry with a bright sheen. Clear resins even dry into a crystal clear cast.

But working with resin can be tricky, and it’s easy to be a bit imprecise. Occasionally, you’ll end up with resin that has a lumpy surface or excess that needs to be removed. Sanding is typically the way to fix issues like these, but are you actually able to sand resin?

Can You Sand Resin?

And how does this affect the clear and polished finish?

Don’t worry! This guide is here to help. We’ll take a look at whether resin is sandable, as well 

as the best way to do it. Not only that, but we’ll also take you through what you should do to maintain your resin’s sheen.

Ready? Then let’s get started!

Can You Sand Resin?

First of all, yes – you can sand resin. However, there are a few things you need to consider before jumping straight into sanding.

Resin is difficult to sand down due to its toughness. Dry resin is very hard, and a lot of the time your sandpaper will wear down before you’re finished with the resin. This can be avoided if you start with a coarser grit, working your way in increments up to finer sandpapers. 

Because sanding involves making scratches on the surface you’re working on, your resin is going to end up very unpolished. If you don’t sand the resin properly, this can leave the resin permanently opaque.

To avoid unsightly scratches, make sure to use finer sandpaper after coarser sanding. This will reduce the larger scratches and make them much less noticeable. You should also polish the resin before adding any other coats to make the resin completely transparent. 

Without proper sanding, your resin can end up looking worse than before you started. However, this guide will walk you through the best way to sand down your resin, and maintain it so it stays polished and clear.

How To Sand Resin

Wet sanding is the recommended method for sanding down resin. The water will help collect resin dust to prevent you from inhaling it, as well as keep the resin cool. The heat generated by friction means your resin is at risk of melting or warping; water cools the resin down, preventing this.

However, dry sanding may be preferable depending on the situation. If your resin is combined with wood, water may cause this to swell or warp. 

Start off with a coarse, waterproof sandpaper, with a grit size between 200-300. While this might seem like the scratches it makes will be too large, it actually makes things much easier in the long run.

One of the common mistakes people make when sanding down resin is starting off with too fine of a sandpaper. This is hard to begin sanding with, as you have to wear down the entire surface with fine grit. If the sandpaper has nothing to work with, you’ll wear down the sandpaper before the resin.

Moving through grit sizes incrementally will make sanding much easier. Every layer will have less to wear down, and you only need to meet the depth of the first sandpaper. This also reduces the risk of your scratches affecting the resin’s surface (but we’ll get to that later).

Rub the resin against the sandpaper, making sure to cover the entire surface. If your resin has a curved edge, turn it as you go to avoid wearing the curve away.

Once you’ve sanded down the resin as much as you need to, move to the next sandpaper.

Repeat this process, increasing the grit size of the sandpaper each time. 

Keep going until you’re using sandpaper with a grit size between 1000 and 1500. This should leave the resin smooth and shining, with all the scratches nearly unnoticeable.

You’ll probably have noticed by now that your resin is nice and clear while it’s wet, but turns opaque when it dries. This effect will be reduced as you work through your sandpapers, but it will still be fairly obvious that your dry resin isn’t clear.

How To Keep Your Resin’s Shine

How To Keep Your Resin’s Shine

Now your resin has been sanded down to the perfect size and smoothness, it’s time to bring back its clarity and sheen.

While using a fine sandpaper has left the surface of your resin as smooth as possible, it will still be covered in tiny scratches. Luckily, there are a couple of easy things you can do to restore the clear surface.

Polishing is a great way to bring back your resin’s shine. Use a resin polish to buff out the tiny scratches and give the resin a gleaming finish. This not only gets your resin to the desired smoothness, but it also helps fill in any remaining roughness.

Give your resin an occasional polish to maintain its shine.

You can also restore your resin’s clarity by adding an extra layer of resin over the top after sanding. The scratches on the surface will give the new resin the perfect grip to stick to, and it will dry to a crystal-clear finish.

You might want to give it a polish before and after doing this to ensure your resin ends up completely transparent.

If you’re going to add a top coat to your resin, make sure you have used a sandpaper with a high grit size. If the scratches on the resin are too big or deep, they may be visible through the top coat and affect your resin’s quality.

Final Thoughts

So now you know how to sand down resin, as well as what to do to maintain it. As long as you use a range of grit sizes and work through to a fine sandpaper, you’ll prevent the buildup of unsightly scratches.

And by polishing your resin and adding an extra layer after sanding, your resin is guaranteed to stay crystal clear.

Now all you need to do is put your knowledge into practice, and you’ll be able to make the perfect resin in no time.


Mark Andrews
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